$Au - Acc username

$branch(name) - Branch attributes

$branch(name) - reference to attribute 'name' of a branch

This pseudo variable gives you access to the “additional branches” only, not to the “main branch”. E.g. if there are 3 clients registered for the same AoR, after lookup() you will have one contact in the “main branch” and two “additional branches”. Using $branch() you can access the additional branches, the main branch can be accessed using $ru and $du. (Note: In branch_routes there is no distinction between the main and the additional branches - the branch_route will be called once for each one of them.)

Starting with 3.1.0, you can assign value per attribute. Index can be used to update a specific branch:

$(branch(attr)[index])= value;

If index is missing, first branch is used. If index is -1 the last branch is used.

Assigning $null to uri attribute will drop the branch, for the rest of attributes will just set the value to null.

$(branch(uri)[2])="sip:test@kamailio.org;transport=sctp";

$br - Request's first branch

$br - reference to request's first branch

It is R/W variable, you can assign values to it directly in configuration file (will add a new branch).

$bR - Request's all branches

$bR - reference to request's all branches

$bf - Branch flags

$bf - reference to branch flags of branch 0 (RURI) - decimal output

It is R/W variable (you can assign values to it directly in configuration file)

$bF - Branch flags

$bF - reference to branch flags of branch 0 (RURI) - hexa output

It is R/W variable (you can assign values to it directly in configuration file)

$bs - Body size

$bs - body size

$ci - Call-Id

$ci - reference to body of call-id header (R/O)

$cl - Content-Length

$cl - reference to body of content-length header

$cnt(pv) - Count number of pvs

$cnt(avp) - return the number of avps

xlog("$$avp(x) fount $cnt($avp(x)) times\n");

$conid - TCP Connection ID

$conid - The TCP connection ID of the connection the current message arrived on for TCP, TLS, WS, and WSS. Set to $null for SCTP and UDP.

$cs - CSeq

$cs - reference to the sequence number in the cseq header. The method in the CSeq header is identical to the request method, thus use $rm to get the method (works also for responses).

$ct - Contact header

$ct - reference to body of contact header

$cT - Content-Type

$cT - reference to body of content-type header

$dd - Domain of destination URI

$dd - reference to domain of destination uri (without port)

$di - Diversion header URI

$di - reference to Diversion header URI

$dip - Diversion "privacy" parameter

$dip - reference to Diversion header “privacy” parameter value

$dir - Diversion "reason" parameter

$dir - reference to Diversion header “reason” parameter value

$dic - Diversion "counter" parameter

$dic - reference to Diversion header “counter” parameter value

$dp - Port of destination URI

$dp - reference to port of destination uri

$dP - Transport protocol of destination URI

$dP - reference to transport protocol of destination uri

$ds - Destination set

$ds - reference to destination set

$du - Destination URI

$du - reference to destination uri

If loose_route() returns TRUE a destination uri is set according to the first Route header.
$du is also set if lookup() function of 'registrar' module finds contact(s) behind NAT. You can
set $du to any SIP URI.

It is R/W variable (you can assign values to it directly in configuration file)

To reset $du:

$du = null;

$fd - From URI domain

$fd - reference to domain in URI of 'From' header

$fn - From display name

$fn - reference to display name of 'From' header

$fs - Forced socket

$fs - reference to the forced socket for message sending (if any) in the form proto:ip:port

It is R/W variable (you can assign values to it directly in configuration file). Transport proto can be omitted when assigning value, in which case it is taken from destination URI of the message.

$ft - From tag

$ft - reference to tag parameter of 'From' header

$fti - Initial From tag

$fti - reference to tag parameter of 'From' header as it was in the initial request (e.g., initial INVITE).

The value From tag in the initial request can be in the To tag, if the request within the dialog is sent by the callee. This variable detect who sent the request within the dialog and returns the proper value that was in the From tag of the request initiating the dialog.

It is exported by rr module and has to be used after loose_route(). The append_fromtag parameter is required to be set to 1 in order to have this variable returning the right value.

$fu - From URI

$fu - reference to URI of 'From' header

It is R/W variable (you can assign values to it directly in configuration file)

$rz - URI Scheme of R-URI

$Ri - Received IP address

$Ri - reference to IP address of the interface where the request has been received

$Rp - Received port

$Rp - reference to the port where the message was received

$sbranch(attr) - Static Branch

$sbranch(attr) - class of variables allowing to manage the values of attributes for static branch. The static branch is internal structure that is used by the functions sbranch_push_ruri() and sbranch_append() from pv module, enabling more flexibility in updating the R-URI (first) branch attributes as well as extra branches (e.g., for parallel forking).

The attr can be any of the supported values for $branch(attr) class of variables – see above for proper details.

$sp - Source port

$stat(name) - Statistics

$su - Source address as URI

$su - returns the representation of source address (ip, port, proto) as SIP URI. If the proto is UDP, then it is not added (being the default transport protocol).

Its value looks like:

"sip:ip:port" -- if proto is UDP
"sip:ip:port;transport=proto" -- if proto is not UDP

Note that WS and WSS are both represented by transport=ws, conforming with the IETF RFC for SIP over WebSocket.

$sut - Source address as full URI

$su - returns the representation of source address (ip, port, proto) as full SIP URI. The proto UDP is added also as transport parameter.

Its value looks like:

"sip:ip:port;transport=proto"

$td - To URI Domain

$td - reference to domain in URI of 'To' header

$tn - To display name

$tn - reference to display name of 'To' header

$tt - To tag

$tt - reference to tag parameter of 'To' header

$tti - Initial To tag

$tti - reference to tag parameter of 'To' header as it was in the SIP response to the initial request (e.g., 200ok to the initial INVITE).

The value To tag in the initial transaction can be in the From tag, if the request within the dialog is sent by the callee. This variable detect who sent the request within the dialog and returns the proper value that was in the To tag of the transaction initiating the dialog.

It is exported by rr module and has to be used after loose_route(). The append_fromtag parameter is required to be set to 1 in order to have this variable returning the right value.

$tu - To URI

$tu - reference to URI of 'To' header

$tU - To URI Username

$tU - reference to username in URI of 'To' header

$Tb - Startup timestamp

$Tb - reference to unix timestamp of the time at which kamailio was started (boot time)

$Tf - String formatted time - cached

$Tf - reference string formatted time

Note: the system time is retrieved only once for each processed SIP message. Subsequent calls of $Tf for same SIP message will return same value.

$TF - String formatted time - current

$TF - reference string formatted time

Note: the system time is computed for each call of $TF. Subsequent calls of $TF for same SIP message may return different values.

$Ts - Unix time stamp - cached

$Ts - reference to unix time stamp

Note: the system time is retrieved only once for each processed SIP message. Subsequent calls of $Ts for same SIP message will return same value.

$TS - Unix time stamp - current

$TS - reference to unix time stamp

Note: the system time is computed for each call of $TS. Subsequent calls of $TS for same SIP message may return different values.

$ua - User agent header

$ua - reference to user agent header field

$avp(id) - AVPs

$avp(id) - the value of the AVP identified by 'id'.

$(avp(id)[N]) - represents the value of N-th AVP identified by 'id'.

The 'id' can be:

“[(s|i):]name” - name is the id of an AVP; 's' and 'i' specifies if the id is string or integer. If missing, it is considered to be string.

“name” - the name is an AVP alias, or if the alias is not found, it is a string name

pseudo variable - if value of pv is integer, id is integer, if string, id is string

$(avp(id)[0]) can be written in shorter form as $avp(id) and $avp(s:name) as $avp(name).

AVPs are special variables that are attached to SIP transactions. It is a list of pairs (name,value). Before the transaction is created, the AVP list is attached to SIP request. Note that the AVP list works like a stack, last added value is retrieved first, and there can be many values for same AVP name, an assignment to the same AVP name does not overwrite old value, it will add the new value in the list.

To delete the first AVP with name 'id' you have to assign to it '$null':

$avp(id)= $null;

To delete all the AVP with name 'id' you have to assign $null to the index '*':

$(avp(id)[*])= $null;

To overwrite the value of the AVP with name 'id' you have to assign the new value to the index '*':

$(avp(id)[*])= newvalue;

The value of an AVP can be integer or string. To assign a value as string, it has to be enclosed in double quotes. To assign the value as integer, it has to be a valid number given without quotes.

$xavp(id) - XAVPs

xavp - extended AVP's - are structures that can store multiple values. They work like a stack, much like AVPs, and are attached to SIP transactions. Each xavp has a name and can contain multiple named values, the structure name and the value name are separated by '⇒' like $xavp(root⇒branch) where “root” is the name of the structure and branch is a named value. To assign a value use

$xavp(root=>branch)="value";

Like avps, xavp act like a stack. To refer to an existing value, use an index. The newest xavp has index zero [0].

$xavp(root[0]=>newbranch)=12;

If you assign a value without an index, a new xavp is allocated and the old one is pushed up the stack, becoming index [1]. Old index [1] becomes [2] etc.

xavps are read and write variables. You can create multilevel xavps, as xavps may contain xavps.

$hdr(name) - Headers

$hdr(name) - represents the body of first header identified by 'name'

$(hdr(name)[N]) - represents the body of the N-th header identified by 'name'.

If [N] is omitted then the body of the first header is printed. The first header is got when N=0, for the second N=1, a.s.o. In case of a comma-separated multi-body headers, it returns all the bodies, comma-separated. To print the last header of that type, use -1, or other negative values to count from the end. No white spaces are allowed inside the specifier (before }, before or after {, [, ] symbols). When N='*', all headers of that type are printed.

The module should identify compact header names. It is recommended to use dedicated specifiers for headers (e.g., $ua for user agent header), if they are available – they are faster.

Example of usage:

if($hdr(From)=~"kamailio\.org"){
...
}

It is read-only variable. You can remove or add headers using functions from textops module.

$var(name) - Private memory variables (zero)

$var(name) - refers to variables that can be used in configuration script, having integer or string value. This kind of variables are faster than AVPs, being referenced directly to memory location.

Example of usage:

$var(a)=2;#-- sets the value of variable 'a' to integer '2'
$var(a)="2";#-- sets the value of variable 'a' to string '2'
$var(a)="sip:"+ $au +"@"+ $fd;#-- compose a value from authentication username and From URI domain
$var(a)=3+(7&(~2));if( $var(a)&4){
xlog("var a has third bit set\n");}

Note: Setting a variable to $null is actually initializing the value to integer '0'. This type of script variables doesn't have $null value.

$var(x)= $null;if($var(x)==0){# this is true
...
}

Note: A script variable persists over the Kamailio process in which it was initialized, so be sure of giving it a new value before reading it or you'll get the value asigned in any other previous message processed by the same Kamailio process (pid).

It is R/W variable (you can assign values to it directly in configuration file)

pv module can be used to initialize the script variables.

$vz(name) - Private memory variables (zero)

Same as $var(name) – added to pair with $vn(name).

$vn(name) - Private memory variables (null)

Similar to $var(name) and able to hold $null (which is the default value). The value is kept in private memory (pkg) and it is persistent across SIP message processing, within the space of each Kamailio process.

Example of usage:

$vn(x)=1;
$vn(x)="abc";
$vn(x)= $null;if($vn(x)== $null){ ... }

$shv(name) - Shared memory variables

$shv(name) - it is a class of pseudo-variables stored in shared memory. The value of $shv(name) is visible across all Kamailio processes. Each “shv” has single value and it is initialised to integer 0. You can use “shvset” parameter of pv module to initialize the shared variable. The module exports a set of MI functions to get/set the value of shared variables.

Erlang module Pseudo-Variables

Erlang pseudo-variable attributes

* format - prints a term, in clear text. It tries to resemble the term printing in the Erlang shell.

$erl_atom(name)

$erl_atom(name) pseudo variable allows create analog to Erlang atom data type.
Erlang atom is a literal, a constant with name. Formatted output pseudo variable
atom could be enclosed in single quotes (') if it does not begin with a
lower-case letter or if it contains other characters than alphanumeric characters,
underscore (_), or @.

TMX module Pseudo-Variables

$T_branch_idx

the index (starting with 1 for the first branch) of the branch for which is executed the branch_route[]. If used outside of branch_route[] block, the value is '0'.

$T_reply_ruid

the ruid stored in the current branch of the transaction. The ruid is stored in a branch from the details in a contact binding. In a event_route[tm:branch-failure] block, this is the ruid of the branch that sent a failure reply. In a failure_route[] block, this is the ruid of the winning failure response.

$T_reply_code

the code of the reply, as follows: in request_route will be the last stateful sent reply; in reply_route will be the current processed reply; in failure_route will be the negative winning reply. In case of no-reply or error, '0' value is returned

$T_req(pv)

can be used in reply routes or inside the modules to get access to attributes of the request belonging to same transaction as the reply

reply_type - 1 if it is a local generated reply, 0 - if no reply for transaction or it is a received reply

Note: the pair (id_index,id_label) uniquely identifies a transaction.

$T_branch(name)

pseudo-variable class to access TM branch attributes

The name can be:

flags - Flags of the branch. In a event_route[tm:branch-failure] block, this is the flags of the branch that sent a failure reply. In a failure_route[] block, this is the flags of the winning failure response.

uri - the R-URI of the branch. Can be used in onreply_route[id] - reply route blocks executed by tm module. For other routing blocks handling requests, the R-URI is returned by $ru

UAC module Pseudo-Variables

$uac_req(key)

used to build the input for uac_send_req() function of UAC module

The key can be:

method - SIP method

ruri - request URI

furi - From URI

turi - To URI

ouri - Outbound proxy URI

hdrs - SIP Headers

body - Body

auser - authentication username

apasswd - authentication password

sock - local socket to be used for sending (proto:address:port)

callid - SIP-Call-ID of the generated request (by default, a call-id is generated)

all - alias useful to reset all fields - $uac_req(all) = $null;

evroute - it has to be set to 1 in order to execute event_route[uac:reply] when reply is received

evcode - reply code for the request sent with uac_req_send(), available inside event_route[uac:reply]

evtype - is 1 if the reply was received via network, 2 if the reply was locally generated (e.g., retransmission timeout), available inside event_route[uac:reply]

Nathelper module Pseudo-Variables

$rr_count

Number of Record Routes in received SIP request or reply.

$rr_top_count

If topmost Record Route in received SIP request or reply is a double Record Route, value of $rr_top_count is 2. If it a single Record Route, value of $rr_top_count is 1. If there is no Record Route(s), value of $rr_top_count is 0.

$tls_my_san_ip

XHTTP module Pseudo-Variables

$hu

MSRP Module Pseudo Variables

This class of pseudo-variables is exported by MSRP module and give access to attributes of MSRP frames.

$msrp(buf)

The entire content of MSRP frame - first line, headers, body and end-line.

$msrp(body)

The body of MSRP frame.

$msrp(code)

The code of MSRP replies.

$msrp(hdrs)

The headers in a MSRP frame.

$msrp(msgid)

The body of Message-Id header.

$msrp(method)

The method of a MSRP request.

$msrp(buflen)

The length of entire MSRP frame.

$msrp(sessid)

The session id for MSRP frame. It is taken from the first MSRP URI in To-Path header.

$msrp(reason)

The reason text in a MSRP reply.

$msrp(crthop)

The URI for current hop - it is the first URI in To-Path header.

$msrp(bodylen)

The length of the body in MSRP frame.

$msrp(transid)

The transaction ID from the first line of MSRP frame.

$msrp(prevhop)

The MSRP URI of the previous hop - the first address in From-Path header.

$msrp(nexthop)

The URI of the next hop - the second address in To-Path header.

$msrp(lasthop)

The last hop URI - the last address in To-Path header.

$msrp(srcaddr)

The address of the previous hop set as MSRP URI using received source IP and port.

$msrp(srcsock)

The local socket where the MSRP frame was received, set as **proto:ipaddr:port“.

$msrp(firsthop)

The URI of the first hop - the last address in From-Path header.

$msrp(prevhops)

The number of previous hops - it is the number of addresses in From-Path header.

$msrp(nexthops)

The number of next hops - it is the number of addresses in To-Path header minus 1 (the first address in To-Path is current hop).

$msrp(conid)

The internal integer id for TCP/TLS connection.

SIPT module Pseudo-Variables

$sipt(calling_party_number.presentation) / $sipt_presentation

Returns the value of the Address presentation restricted indicator contained in the Calling Party Number header of the IAM message if it exists. Returns -1 if there isn't a Calling Party Number header.

$sipt(calling_party_number.screening) / $sipt_screening

Returns the value of the Screening Indicator contained in the Calling Party Number header of the IAM message if it exists. Returns -1 if there isn't a Calling Party Number header.

$sipt(hop_counter) / $sipt_hop_counter

Returns the value of the Hop Counter for the IAM message if it exists. Returns -1 if there isn't a hop counter.

$sipt(calling_party_category) / $sipt(cpc) / $sipt_cpc

Returns the value of the Calling Party Category for the IAM message. Returns -1 if there is a parsing error.

Returns the value of the Nature of Address Indicator of the Called Party for the IAM message. Returns -1 if there is a parsing error.

$sipt(event_info)

Returns the value of the Event Info header of the CPG message. Returns -1 if there is a parsing error.

$cfg(key) - Config File Attributes

Attributes related to configuration file.

The key can be:

line - return current line in config

name - return the name of current config file

Example:

send_reply("404","Not found at line $cfg(line)");

$dns(pvid=>key) - DNS Query Result

This variable stores the DNS result details after a call of dns_query(hostname, pvid) function from ipops module.

pvid can be any string

key can be:

count - number of addresses

ipv4 - set to 1 if at least one ipv4 address (otherwise 0)

ipv6 - set to 1 if at least one ipv6 address (otherwise 0)

addr[index] - the address as string from position index in the list (0 based indexing)

type[index] - the type of address from position index in the list (0 based indexing), the value is 4 for ipv4 and 6 for ipv6

The index can be an integer or a variable with integer value. First address has the index 0. If negative value, the returned address is counted from the end of the list, -1 being the last address. If no index is provided, then the first address is returned.